There is a need for a compact drive unit composed of three or more reversible sections which have the capability of being moved either in unison or separately. One use for such a drive unit is for powering the floor members of a reciprocating floor conveyor.
Basically considered, a reciprocating floor conveyor comprises at least one group of at least three elongated floor members and a hydraulic drive system which operates to drive at least a majority of the floor members in unison in the desired conveying direction, and to retract them individually. Systems are in use in which all of the floor members are driven in unison, in the desired conveying direction, and are then individually retracted sequentially. It has also been proposed to drive a majority of the floor members in the desired conveying direction while at the same time retracting the remaining floor slat members The present invention has application for both types of systems.
For background purposes, reference is made to my U.S. Pat. No. 4,793,469, granted Dec. 27, 1988, and entitled Reduced Size Drive/Frame Assembly For A Reciprocating Floor Conveyor, and all of the prior art that is disclosed in such patent. U.S. Pat. No. 4,793,469 discloses and claims a simplified hydraulic drive assembly which comprises a plurality of parallel hydraulic units, each having fixed opposite end portions and a travelling center portion. The travelling and fixed portions define variable volume fluid chambers. Each travelling portion is connected to a transverse drive beam. Each transverse drive beam is connected to one set of the floor members. The drive unit embodiment disclosed by U.S. Pat. No. 4,793,469 has a fixed piston rod and a travelling cylinder body.
A principal object of the present invention is to provide a hydraulic drive which when compared to the hydraulic drive disclosed by U.S. Pat. No. 4,793,469 is further simplified and further reduced in size.
The contents of my aforementioned U.S. Pat. No. 4,793,469 and my copending application Ser. No. 189,540 are both hereby fully incorporated by reference into the subject application.